1. Field of the Invention
This invention relates to a solid cast composition containing an active chlorine source suspended in a substantially waxy carrier.
2. Background
Detergent products formulated with high levels of an active chlorine source, such as a chlorinated isocyanurate, tend to liberate chlorine gas in response to a variety of conditions. Chlorine gas is highly toxic and can be reactive to the point of causing spontaneous ignition. Heat, acidity, and moisture are conditions especially tending to promote chlorine gas liberation in these products. For example, heat normally causes the active chlorine source to liberate chlorine gas. Thus, manufacturing and storage conditions dictate constraints on the use of active chlorine sources such as those above. Active chlorine sources are typically affected by low pH conditions favoring chlorine gas liberation. Hence, the presence of acidic materials in proximity to active chlorine sources must be considered in manufacturing an active chlorine-containing composition.
Yet another factor which must be considered in manufacturing a detergent product containing an active chlorine source is water, which also promotes chlorine gas liberation from these compounds. In detergent products containing a strong base such as sodium or potassium hydroxide and an active chlorine source, an exothermic reaction between the active chlorine source and the base may form water. The water, in turn, promotes liberation of chlorine gas from the remaining active chlorine source. Moreover, heat generated from these exothermic reactions further promotes chlorine gas liberation from the active chlorine source. The water, formed from the reaction from the strong base and a proton donating substance, further promotes dispersion of the strong base and the other ingredient reacting with the strong base. The dispersed strong base then reacts with more of the active chlorine source to liberate still more chlorine gas. These effects, therefore, promote or accelerate the reaction to completion by releasing further quantities of heat and water as the reaction proceeds. Moreover, if the source of alkalinity (the strong base) is sufficiently depleted, the liberated chlorine gas may combine with water to form an acid, thereby further reducing the pH in the vicinity of the active chlorine source. This, in turn, still further promotes the liberation of chlorine gas from the active chlorine source. Hence, manufacturing substantially solid cast chlorinated cleaning compositions requires combining carefully selected ingredients under strictly controlled manufacturing conditions.
Normally, one skilled in the art would avoid using ingredients which liberate chlorine gas when combined in a single product. One alternative to avoiding ingredient combinations favoring chlorine liberation from an active chlorine source is to stabilize the conflicting ingredients before or during the manufacturing process.
U.S. Pat. No. 3,908,045, issued to Alterman et al., Sep. 23, 1975, discloses particles of a fluidizable substance coated with a non-aqueous solution. Disclosures similar to U.S. Pat. No. 3,908,045 are found in U.S. Pat. No. 3,983,254, issued to Alterman et al., Sep. 28, 1976.
U.S. Pat. No. 4,655,780, issued to Chun et al., Apr. 7, 1987, discloses hard spherical bleaching particles utilizing an active halogen oxidizing material. U.S. Pat. No. 4,657,784, issued to Olson et al., Apr. 14, 1987, discusses the use of encapsulated halogen bleaches. U.S. Pat. No. 4,731,195, issued Mar. 15, 1988 to Olson et al. (a divisional application of U.S. Pat. No. 4,657,784), contains similar disclosures.
The use of an active halogen bleach encapsulated with a synthetic detergent such as sodium octyl sulfonate is disclosed in U.S. Pat. No. 4,681,914, issued Jul. 21, 1987 and in U.S. Pat. No. 5,407,598 issued Apr. 18, 1995, both to Olson et al.
U.S. Pat. No. 5,213,705, issued May 25, 1993 to Olson, also discloses an active halogen bleach encapsulated with a synthetic detergent. Chun et al., in U.S. Pat. No. 4,707,160, issued Nov. 17, 1987, discloses particles with a core containing a halogen bleach. U.S. Pat. No. 5,133,892, issued Jul. 28, 1992 to Chun et al., discloses a multi layer detergent tablet.
Aronson et al., in U.S. Pat. No. 4,863,632 issued Sep. 5, 1989, disclose a bleaching particle having an oxidizing material surrounded by a polycarbonate coating. U.S. Pat. No. 5,358,653, issued to Gladfelter et al., Oct. 25, 1994, discloses a cleaning product containing a chlorine source.
U.S. Pat. No. 5,929,011, issued to Scepanski, Jul. 27, 1999 and assigned to the assignee of the present invention, discloses a solid cast detergent product containing an active chlorine source suspended in a free fatty acid.
Other than as 100% free fatty acids, none of the foregoing references, however, discloses using the waxy ingredients or combination of waxy ingredients of this invention in a substantially solid cast composition as utilized in the present invention to prepare a stable detergent composition with an active chlorine source. This method of manufacture advantageously results in a stable solid cast composition with ingredients previously considered to be incompatible with an active chlorine source. Moreover, the waxy ingredients disclosed herein enable solid cast compositions to be made with more widely available dispensing choices than using 100% fatty acids. Moreover, when a combination of waxy substances without free fatty acids is used with hard water (with divalent cations) the end result is clean garments free from the dinginess of precipitated free fatty acid-divalent salts. Furthermore, the waxy substances of the present invention still impart a softness to laundered articles to reduce or eliminate the harsh feel. In contrast to free fatty acids, this softening property is present even when using hard water.
Surprisingly, by practicing the present invention as described herein, the challenge of manufacturing such a highly desirable product becomes manageable. Specifically, the present invention provides important advantages, including: (1) minimizing or eliminating chlorine liberation; (2) preventing the detergent builder (if present) from acting hygroscopically; and (3) promoting dispersion of the ingredients by inclusion of the detergent builder (if present).
To the extent that the foregoing references are applicable to the present intention, they are herein incorporated by reference. Temperatures specified herein are in degrees F., unless other wise indicated. throughout the specification and claims, percentages and ratios are by weight, unless otherwise indicated. Percentages are based upon the combined weight of the component recited in the pertinent claims. Ranges and ratios specified herein may be combined.